Dsc Part Addons Tutorial
Introduction This is a brief description of the parameters recognized by Celestia v1.4.1 in DSC files (Deep Space Catalogs). DSC Galaxy functionality has undergone a substantial improvement when compared to the previous versions of Celestia. A DSC catalog file can be used to describe four classes of objects: OpenCluster, Globular (i.e. Globular Cluster), Nebula or Galaxy. A DSC object definition consists of its class, a quoted name, and its parameters enclosed in braces: ''Class '' "name" { ...parameters... } List of Parameters Class: * OpenCluster "name" * GlobularCluster "name" * Nebula "name" * Galaxy "name" Location: * RA f'', '''Dec' f'', '''Distance' f'' or * '''Position' [f'' ''f f''] Orientation: * '''Axis' [f'' ''f f''] * '''Angle' f'' Size: * '''Radius' f'' Information: * '''InfoUrl' "URL" Appearance: * Mesh "filename" * Type "string" * CustomTemplate "filename" * AbsMag f'' or '''Appmag' f'' OpenCluster "''name" "name" is the name of the object. Multiple names can be speciied within the quotes if they're separated by colons (:). OpenCluster currently is used only to associate the specified "name" with a position in space. The members of an OpenCluster are defined separately in one or more .STC files or in stars.dat. The parameters used to define an OpenCluster are placement A deep space object's position can be defined either by specifying a single position vector or by specifying its three astronomical coordinates. * Position [ f f f ] The position vector's y z coordinates are in Light Years, specifying a position in Celestia's Ecliptic J2000 "Universal" coordinate system * or * Distance number (default: 1.0) in LightYears * RA number (default: 0.0) Right Ascension in fractional Hours (unlike STC catalogs, which use fractional degrees) * Dec number (default: 0.0) Declination in fractional degrees orientation (optional) * Axis 3 vector (default: [ 1.0 0.0 0.0] ) a unit vector specifying the orientation of the object's axis in Celestia's Ecliptic J2000 "Universal" coordinate system * Angle number (default: 0.0 degrees) the amount the object is rotated around that Axis. size * Radius number (default: 0.0) in Light Years. information (optional) * InfoUrl "string" "string" should be the URL of a web page describing the object. Globular "name" Places a glowing spherical image of stars at the specified position. Uses all of the parameters used for OpenCluster plus the following: shape * Detail number * CoreRadius number * KingConcentration number or * CustomTemplate "filename" (optional) : "filename" must be a the name of a PNG image defining the shape of this GlobularCluster. example Globular "M 4:NGC 6121:GCl 41:C 1620-264" { RA 16.3931 # hours Dec -26.5253 # degrees Distance 7176 # ly Radius 37.57 # ly, mu25 Isophote CoreRadius 0.83 # arcmin KingConcentration 1.59 # c = log10(r_t/r_c) AbsMag -7.2 # mags Axis [ 0.1967 -0.6744 -0.7117] Angle 171.8 # degrees InfoURL "http://simbad.u-strasbg.fr/sim-id.pl?Ident=NGC 6121" } Nebula "name" Places a glowing model at the specified position and orientation. Uses all of the parameters used for OpenCluster plus the following: shape * Mesh "filename" (optional) : "filename" must be the name of a 3DS, CMS or CMOD model file which determines the Nebula's shape. : The model's internal material may require an associated PNG, JPG or DDS surface texture image file to be in the object's subdirectory /textures/medres to define the Nebula's coloration. : If Mesh is omitted, no object is drawn. Galaxy "name" Places a glowing image of a galaxy at the specified position and orientation Uses all of the parameters used for OpenCluster plus the following: shape * Type "string" "string" should be one of: S0,Sa,Sb,Sc,SBa,SBb,SBc,E0,E1,E2,E3,E4,E5,E6,E7,Irr : The Type is shown in Celestia's on-screen informational display. It also determines which PNG image in Celestia's Models directory is used to define the shape of the Galaxy's image. or * CustomTemplate "filename" (optional) "filename" must be a the name of a PNG image defining the shape of this Galaxy. brightness * AppMag number or * AbsMag number Example Nebula "M 16" ' '{ Mesh "1995-44-a.3ds" Axis -0.737927 -0.642989 Angle 146.298 RA 18.31404 Dec -13.8311 Distance 7002 Radius 3.45 } Category:Tutorial‏‎